This is an example of why I believe there is a bias in the media that favors Democrats over Republicans. I have watched for years how the party affiliation of politicians involved in "positive" stories and "negative" stories is identified. I've long noticed a trend: That the party affiliation of Democrats in negative stories is buried, while the party affiliation of Republicans in negative stories is generally in the first reference to the person.
The latest story is one of a New York state senator who has been indicted on assault charges. A journalist is supposed to mention the politician's party affiliation (you often see it as D-NY or something like that) early on. Instead, this reporter waited until the last paragraph in the whole article, and even then referenced his "fellow Democrats."
I don't have quantitative evidence of this, but over the years I've noticed this trend over and over.